Massive Subsurface Ice Deposits in Southern Hemisphere, MARSIS results - LPSC 2006 Options

[Guest_paulanderson_*]

Thanks to Doug for pointing out this LPSC update:

Mars Express: Probing the Depths
ftp://ftp.lpi.usra.edu/pub/outgoing/lpsc2006/full102.pdf

Another good article:

Martian Ice: Wide and Deep
http://skyandtelescope.com/news/article_1695_1.asp

"More recently, a shift in Mars Express's orbit has allowed MARSIS to probe the planet's south pole. There the buried ice extends down to 3½ kilometers (2 miles) under the cap in some places. Water ice appears quite transparent at radar wavelengths, and the ease with which MARSIS's signal penetrates the polar terrain suggests that the ice is relatively pure. "There's at most only a few percent of impurities," team coleader Jeffrey Plaut (Jet Propulsion Laboratory) told planetary scientists meeting in Houston this week.

Potentially more exciting is MARSIS's discovery that huge quantities of ice may underlie a large plain beyond the southern cap called Dorsa Argentea, which covers 3 million square kilometers, about 2% of the planet's surface. Geologists originally thought Dorsa Argentea was a volcanic plain, but James W. Head III (Brown University) and others recently realized that a broad ice sheet must lie beneath its dusty surface. Plaut reported that MARSIS has found multiple layers stacked beneath Dorsa Argentea to depths of up to 500 meters — and if they’re all ice, they represent a reservoir large enough to cover the entire planet with water to a depth of about 10 meters (30 feet)."

[Bart]

While that's great news, I think the comment about covering the whole planet to a depth of 10 meters is a bit misleading. They just took the 500m depth of the deposit and multiplied it by the 2% of the Martian surface that it covers - that gives 10m. If you melted the whole Dorsa Argentea deposit, taking the actual relief of the Martian surface into account, you'd wind up with something like image #9 on Magnus Lundstedt's Water Oceans on Mars page.

Bart

[Guest_paulanderson_*]

Also:

Big New Reservoir of Water Ice Suspected Under Mars
http://www.newscientistspace.com/article/d...under-mars.html

[helvick]

you'd wind up with something like image #9 on Magnus Lundstedt's Water Oceans on Mars page.

Serioius props to Magnus for having a relevant model to put some PR science to the test at just the right time.
Also excellent point Bart by the way - excellent use of the material on hand.

[Guest_paulanderson_*]

Regardless of how much of the surface may be theoretically covered by any melted ice, there is apparently a lot of subsurface ice, both "wide and deep" as New Scientist puts it, a very significant finding... I look forward to MRO's studies.

[ljk4-1]

'Hourglass'-shaped crater - new video and perspectives

This video and accompanying images, taken by the High Resolution Stereo Camera
(HRSC) on board ESA's Mars Express spacecraft, show an unusual flow deposit on
the floors of two adjacent impact craters in the eastern Hellas Planitia region,
indicating possible glacial processes.

Full story at:

http://www.esa.int/SPECIALS/Mars_Express/SEM618NVGJE_0.html

[Guest_BruceMoomaw_*]

The business about there being lots of ice under Dorsa Argentea is something important that they really did manage to keep under wraps until the actual LPSC conference -- there's not a whisper about it in any of the abstracts.

[edstrick]

Mariner 7 saw a ragged semi-circular scarp in the south Polar region that I believe corresponds to a degraded and mostly buried impact basin. MOLA data shows it rather well. I wonder if the deepest 3.5 km thicknesses inferred for the dusty ice deposits penetrated by MARSIS are in layered deposits superimposed on the depressed region corresponding to this basin?

[jaywee]

I haven't seen this mentioned on the forum yet - there was very interresting MARSIS lecture by Dr. Jeffrey Plaut, co-PI of MARSIS. link

[Harder]

I just received the new ESA Bulletin and it is mentioned that "The MARSIS radar has made significant discoveries during the last nighttime season; they will be published shortly"
Let's hope we'll be on the front-row when the discoveries are published. I'm not aware that we have an ESA equivalent of Dr. Stern in our midst but it is never too late of course
Peter

[Harder]

Time has passed... we now write 16th Oct as the day when a new trickle of info is published:

http://www.esa.int/SPECIALS/Mars_Express/SEMADOV74TE_0.html

[MahFL]

So there is plenty of water for the heated swimming pools when we colonise the place.

[ElkGroveDan]

I can appreciate the artistic enhancement that is added in many of these Mars Express images, but that image of Vastitas Borealis is just plain weird looking. Does anyone know if this is an overlay of a MARSIS image? Or just some over-zealous image retouching?

http://www.esa.int/SPECIALS/Mars_Express/SEMADOV74TE_0.html

[ustrax]

News from OMEGA:
Did I read "geyser"?...

[nprev]

Yes, you did...now let's see ME and/or MRO prove it!